Electrical connector



United States Patent '1 2,742,625 ELECTRICAL CONNECTOR James R. Bird, Chagrin Falls, and Henry J. Calderhead,

Cleveland, Ohio, assignors to Bird Electronic Corporation, Cleveland, Ohio, a corporation of Ohio Application July 14, 1950, Serial No. 173,776

12 Claims. (Cl. 339176) This invention relates to electrical connecting devices, more particularly to an electrical connector for use in combination with a cable having a center conductor and an outer tubular sheath preferably of conductive metal. Reference is made to copending application for United States patent, Serial No. 72,782 filed January 26, 1949, and to copending application for U. S. patent, Serial No. 99,474 filed June 16, 1949, now Patent 2,636,120 issued April 21, 1953, on Combined Voltage Divider and Crystal Cartridge Assembly for High Frequency Electrical Devices, both owned by the assignee of the present application, disclosing the present connector in connection with a high frequency electrical measuring device.

One of the principal objects of the present invention is to provide an improved detachable connector combination for use with a shielded conductor. More specifically, it is sought to provide such a connector incorporating separable outer parts which function as a sheath or housing for the center conductor means.

Another object is to provide an electrical connector having separable parts and which incorporates dust-proof and moisture-proof sealing means.

Another object is to provide an improved center conductor cable connector having a side opening through which electrical contact is effected. in a preferential arrangement the side opening connector incorporates swivel means permitting shifting of the connector to different radial positions about the axis of the side opening.

A further and more specific object is to provide a connector employing coil contact means permitting greater tolerance in alignment of parts and greater variation in mating contact size. As a specialized aspect of this phase of the invention, there is provided a multiple function spring contact which frictionally engages both a mating contact of the companion connector part and the center conductor of the sheathed cable.

Other and more general objects and advantages pertaining to certain novel features of construction and combinations and arrangements of parts obtaining simplicity and economy are set forth in the following detailed description. This description is made in connection with the accompanying drawings, forming a part of the specification. Like parts throughout the several views are indicated by the same letters and numerals of reference.

In the drawings:

Figure l is an elevational detail, partly diagrammatic, partly in section and with parts broken away and removed, showing the electrical connector of the present invention as used in a high frequency electrical measuring instrument; and

Fig. 2 is a sectional detail, with parts removed, taken substantially along the line indicated at 22 of Fig. l.

The device of the present invention, although of utility in numerous types and kinds of electrical equipment. is particularly desirable in high frequency electrical circuits. A characteristic use of the connector is in the galvanometer circuit of a high frequency measuring instrument such as that disclosed in the patent referred to. In that instrument, a sampler or voltage divider assembly D is mounted on frusto-conical connector 7 of the tapered transition section of a coaxial line terminating unit. The connector 7 is disposed between the large diameter end of the horn conductor (not shown) of a conventional line terminating device and a coaxial transmission line. The small di- 2,742,625 Patented Apr. 17, 1956 ameter end of the connector 7, which is joined to the coaxial transmission line, receives a turned tubular metal fitting 16. A metal sleeve, a fragment of which is shown at 17 and which connects to the outer conductor of the coaxial line, has a collar 19 on one end. The collar has a circular internal rabbet which receives a'pilot flange on the fitting lo and is held to the latter by screws 20. The joint is made fluid-tight as by a resilient 0-ring (not shown) compressed between the end of the sleeve 17 and a flanged retainer ring 22 seated against a circular shoulder on the fitting 16.

Extending axially through the tapered conductor 7, but not shown in the drawings, is the center conductor of the coaxial line terminating structure. In the instrument referred to, measurement is made of the voltage between such center conductor and the tapered connector 7, this measurement being taken at the entering end of the line terminating device. Such voltage measurement is effected by means that includes a capacitance voltage divider arrangement, parts of which are incorporated in the sampler D. A hollow metal body member 70 is attached to the connector 7 as by soldering or brazing and is formed with a central chamber 71 which communicates with the annular space between the center conductor of the coax and the connector 7 through an opening 72 in the latter. A conductive tree structure is supported in the body 70 and comprises a stem 73 having a number of branches. One end of the stem is adjustable in length and includes a metal probe 74 which projects through the opening 72 into the space between the line conductors. This probe and the inner conductor of the line structure comprise adjustable capacitor C1 of the voltage divider combination. The probe 74 is adjusted by a hex ended rod passed axially into the stem 73 through a bore 77, the rod being received in a mating hex socket 78 formed in the body of the probe.

The ends of the probe and of the stem are received and enclosed in an insulating cup 80 which serves as a seal for the opening into the divider body 7%). A threaded counterbore at the inner end of the body passage carrying the cup 80'receives a threaded washer 82 which compresses a washer 83 against the flanged end of the cup to hold the latter in place.

Another branch of the tree structure comprises a rod or condenser element that extends laterally into a radial opening in the body 7 0 and an aligned opening in an extension 88 formed on or attached to the body. The rod is separated from the walls of the body opening and the walls of the extension 38, these parts constituting capacitance C-2 of the voltage divider.

Across the body chamber 71 from the structure of the capacitor C-2 is a rectifier assembly such as a converter crystal or crystal diode. The details of this assembly are omitted herein. It includes, however, a tubular retainer or sleeve on the body 70 which serves as a housing for the crystal diode unit. This crystal unit is held in place by a conductive metal cap llil held captive by link chain 118.

A third branch of the tree structure within the body 70 of the voltage divider D comprises a resistor R connected in series between the stem 73 and one terminal of a galvanometer G. To complete the measuring circuit, the other terminal of the galvanometer is connected to the body 70 through the connector of the present invention, to be later described. The resistor R may comprise a carbon coated glass tube or rod encased within an insulating body 122. Wires 123 and 124 from the ends of the resistor are connected to the stem 73 and to a metal terminal plug 125. The plug 125 is supported by an insulating tube or body 126 held in an externally threaded tubular metal fitting 127 screwed into a threaded counterbore of thebody member 70. The inner end of the fitting 127 is counterbored to receive a button or bypass capacitor C-3. This capacitor includes an outer metal ring 132 soldered or frictionally engaged in the fitting 127. After assembly of the voltage divider D, the chamber 71, which is formed with an opening through the end of the body 70, is closed as by a threaded metal plug 148.

Over the outer end of the tubular fitting 127 is received a side opening hollow metal connector fitting 133 having a threaded metal swivel collar 134 which engages the threads on the tubular fitting 127. The collar embraces that portion of the body or fitting 133 in which is formed the side opening and the collar has a radial flange 128 retentively received for free rotation behind a circular shoulder on the fitting body. A helical coil compression spring 135 of conductive metal is disposed within a chamher 129 in the upper end of the fitting 133, the spring being substantially completely housed within and insulated from the walls of the metal fitting by a hollow plastic enclosure comprising an insulating disc 136 and a cup 137. This cup, positioned bottom end out in the fitting chamber, is of stiff insulating plastic such as polytetrafluoroethylene or similar dielectric and has a central bottom opening 134) which admits the rounded end of the terminal 125 so that the latter makes electrical contact with bent over end turn 131 of the metal spring 135. A resilient O-ring 138 of material such as rubber is received in a circular rabbet in the side face of the fitting 133 and embraces the end of the plastic cup 137. The O-ring is interposed between the fitting 133 and the end face of the tubular fitting 127 to provide a dust and moisture proof seal. It also frictionally resists relative turning between the connector fitting and the device to which the latter is attached. Electrical connection is established between the swivel fitting 133 and the body '70 of the voltage divider D by the metal of the tubular fitting 127 and the collar 134.

A flexible coaxial cable comprising a central wire or conductor 140 and a flexible sheath 141 of woven Wire or the like connects the galvanometer G to the voltage divider D. The center conductor is surrounded by a flexible tube 142 of dielectric insulating material which spaces the woven sheath 141. A protective sheath or covering 143 of suitable wear resistant composition surrounds the woven conductor 141. The center conductor 140 and the tubular insulation 142 are received coaxially in a circular bore 145 formed in one end of the fitting 133. I

In attaching the flexible cable to the fitting 133 the protective outer sheath 143 is first stripped away from an end portion of the cable and the woven sheath is turned back. The center conductor 140 extends through the entire length of the bore 145 and the tip is bared and extended through a lateral opening in the insulating cup 137, being received and pinched between the turns of the coil 135 which thus makes electrical connection there with. The outer end of bore or passage 145 in the swivel fitting is formed with a counterbore having inner tapered and outer threaded portions. A threaded ferrule 146 surrounds the flexible cable and compresses an insulating plastic jam washer 149 and a rounded end metal jam washer 150 in the tapered portion of the counterbore to clamp the end of the flexible cable and to efiect positive electrical connection between the curled back or reversely turned end of the woven sheath 141 and the fitting 133.

One terminal of the galvanometer G is connected to the center conductor 140 and the other terminal is connected to the conductive sheath or outer conductor 141 of the coaxial cable.

In operation, the voltage drop or potential difference across the coaxial line is divided between the capacitors C-1 and C-Z inversely proportioned to their capacitances. The capacitor C2 is charged by the action of the crystal diode rectifier to a direct current voltage substantially equal to the peak value of the prevailing high frequency voltage in the line and the galvanorncter G indicates the direct current voltage across the capacitor C2. The cable connecting device of the present invention insures positive electrical connection between the parts of the cable and the components of the voltage divider and permits the galvanometer to be easily disconnected for service or transit.

In accordance with the patent statutes the principles of the present invention may be utilized in various ways, numerous modifications and alterations being contemplated, substitution of parts and changes in construction being resorted to as desired, it being understood that the device shown in the drawings and described above is given merely for purposes of explanation and illustration without intending to limit the scope of the claims to the specific details disclosed.

What we claim and desire to secure by Letters Patent of the United States is:

1. In combination in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other mem' her. a hollow substantially cylindrically shaped insulating element disposed within one of the body members an having a substantially cylindrical chamber therein, a substantially cylindrical coil spring disposed within the insulating element in coaxial relation to the chamber in the latter and substantially filling such chamber, said insulating element having an opening continuous with. the opening in the one body member, the insulating element substantially surrounding the spring to insulate the latter from the one body member and the opening in the insulating element being smaller than the spring whereby to retain the spring captive in the insulating element, means for drawing the parts together and holding the body members with their openings in registry, a contact terminal and insulating means supporting the contact terminal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the opening in the insulating element for engagement with the spring inside the latter.

2. In combination in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other member, a hollow substantially cylindrically shaped insulating element disposed within one of the body members and having a substantially cylindrical chamber therein, a substantially cylindrical coil spring disposed within the insulating element in coaxial relation to the chamber in the latter and substantially filling such chamber, said insulating element having an opening continuous with the opening in the one body member, the insulating element substantially surrounding the spring to insulate the latter from the one body member and the opening in the element being smaller than the spring whereby to retain the spring captive in the insulating element, means for drawing the parts together and holding the body members with their openings in registry, a flexible cable, means for securing the cable to said one hollow body member, the cable including a conductor extending into the hollow insulating element and in engagement with the spring, a contact terminal and insulating means supporting the contact terminal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the opening in the insulating element for engagement with the spring inside the latter.

3. In combination in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other memher, a hollow insulating element having a substantially cylindrical wall, said insulating element being disposed Within one of the body members and providing a substantially cylindrical spring chamber, a coil spring in said chamber, insulating means across the ends of the spring chamber toretain the spring in the latter and to insulate the retained spring from the body member in which it is retained, a flexible cable, means for securing the cable to said one body member, the cable including a conductor extending through the cylindrical wall of the insulating element and engaging the coil spring, the insulating means across one end of the spring chamber being formed with an opening smaller than the spring and continuous with the opening in said one body member, means for drawing the parts together and holding the body members with their openings in registry, a contact terminal and insulating means supporting the contact terminal in the other bod-y member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the openings in the insulating means to engage the coil spring within the cylindrical spring chamber.

4. In combination in an electrical'connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other member, a hollow substantially cylindrically shaped insulating element disposed within one of the body members and having a substantially cylindrical chamber therein, a substantially cylindrical coil spring disposed within the insulating element in coaxial relation to the chamber in the latter and substantially filling such chamber, said insulating element having an opening continuous with the opening in the one body member, the insulating element substantially surrounding the spring to insulate the latter from the one body member and the opening in the element being smaller than the spring whereby to retain the spring captive in the insulating element, means for drawing the parts together and holding the body members with their openings in registry, a contact terminal and insulating means supporting the contact terminal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the opening in the insulating element for engagement with the spring inside the latter, the contact terminal having a ubstantially uniform cross sectional shape along its length, said cross sectional shape being complemental to the shape of the opening in the insulating element to effect a seal therewith.

5 in combination in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other member, a hollow insulating element disposed within one of the body members, a coil spring disposed within the insulating element, said insulating element having an opening continuous with the opening in the one body member, the element substantially surrounding the spring to insulate the latter from the one body member and the opening in the element being smaller than the spring whereby to retain the spring captive in the insulating element, means for drawing the parts together and holding the body members with their openings in registry, a resilient deformable sealing ring disposed about the opening in said one body member, said ring being in sealing engagement with the insulating element about the entire circumferential extent of the ring and being arranged for confinement between the body members when the parts are drawn together to effect a seal therebetween while maintaining said sealing engagement with the insulating element, a contact terminal and insulating means supporting the contact tert 6 minal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the opening in the insulating element for engagement with the spring inside the latter.

6. in combination in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in onemember positioned in registry with the opening in the other member, a hollow insulating element disposed within one of the body members, a coil spring disposed within the insulating element, said insulating element having an opening continuous with the opening in the one body member, the element substantially surrounding the spring to insulate the latter from the one body member and the opening in the element being smaller than the spring whereby to retain the spring captive in the insulating element, means for drawing the parts together and holding the body members with their openings in registry, a resilient deformable sealing ring disposed about the opening in said one body member, said ring being in sealing engagement with the insulating element about the entire circumferential extent of the ring and being arranged for confinement between the body members when the parts are drawn together to eliect a seal therebetween while maintaining said sealing engagement with the insulating element, a contact terminal and insulating means supporting the contact terminal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the opening in the insulating element for engagement with the spring inside the latter, the contact terminal having a substantially uniform cross sectional shape along its length, said cross sectional shape being complemental to the shape of the opening in the insulating element to effect a seal therewith. i

7. A component for use in an electrical connector 0 the type in which a pair of separable components having hollow bodies and openings into the interiors thereof are coupled together with their openings in confronting relation and separable elements carried by the bodies in insulated relation effect contact with one another, said component comprising a hollow body having a chamber and a passage intersecting the chamber intermediate the ends of the latter, the body being formed with an opening into the chamber, a hollow insulator in the chamber, the body chamber having walls contacting and confining the walls of the insulator throughout substantially ,the entire length of the insulator, a coil spring within the insulator and electrically insulated from the body by the insulator walls confined and contacted by the body walls, an opening in the insulator continuous with the passage to admit into the interior of the insulator a wire conductor projected into the chamber from the passage, the coil spring being adapted to receive such a projected wire conductor between its turns and thereby etfect an electrical contact maintained by yielding pressure of the spring against such Wire, and the insulator having an opening continuous with the body opening to admit a contact terminal carried by another connector component into the interior of the insulator upon coupling together the components for effecting electrical contact with the spring, the last mentioned electrical contact also being maintained by yielding pressure of the spring against the terminal.

8. A component for use in an electrical connector of the type in which a pair of separable components having hollow bodies and openings into the interiors thereof are coupled together with their openngs in confronting relation and separable elements carried by the bodies in insulated relation effect contact with one another, said component comprising a hollow body having a chamber and a passage intersecting the chamber, the axis of the passage being at an angle to the axis of the chamber and the body being formed with an opening into the chamber, a hollow insulator in the chamber, the body chamber having walls contacting and confining the walls of the insulator throughout substantially the entire length of the insulator, a coil spring within the insulator with the spring axis angularly disposed relative to the passage axis, an opening in the insulator continuous with the passage to admit into the interior of the insulator a wire conductor projected into the chamber from the passage, the coil spring being adapted to receive such a projected wire conductor between its turns and thereby efiect an electrical contact maintained by yielding pressure of the spring against such wire, and the insulator having an opening continuous with the body opening to admit a contact terminal carried by another connector component into the interior of the insulator upon coupling together the components for effecting electrical contact with the spring, the last mentioned electrical contact also being maintained by yielding pressure of the spring against the terminal.

9. A component for use in an electrical connector of the type in which a pair of separable components having hollow bodies and openings into the interiors thereof are coupled together with their openings in confronting relation and separable elements carried by the bodies in insulated relation efi'ect contact with one another, said component comprising a hollow body having a chamber and a passage intersecting the chamber, the axis of the passage being at an angle to the axis of the chamber and the body being formed with an opening into the chamber, a hollow insulator in the chamber, the body chamber having walls contacting and confining the walls of the insulator throughout substantially the entire length of the insulator, a coil spring within the insulator with the spring axis angularly disposed relative to the passage axis, an opening in the insulator continuous with the passage to admit into the interior of the insulator a wire conductor projected into the chamber from the passage, the coil spring being adapted to receive such a projected wire conductor between its turns and thereby effect an electrical contact maintained by yielding pressure of the spring against such wire, and the insulator having an opening continuous with the body opening to admit a contact terminal carried by another connector component into the interior of the insulator upon coupling together the components for effecting electrical contact with the spring, the last mentioned electrical contact alsobeing maintained by yielding pressure of the spring against the terminal, the deflection of the spring under the pressure of such contact terminal being arranged to augment the contact pressure between the spring and a wore conductor projected between the turns of the spring.

10'. in combination in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other member, a hollow insulating element disposed within one of the body members, a coil spring disposed within the insulating element, said insulating element having an opening continuous with the opening in the one body member, the element substantially surrounding the spring toinsulate the latter from the one body member, means for drawing the parts together and holding the body members with their openings in registry, a resilient deformable sealing ring disposed about the opening in said one body member, said ring being in sealing engagement with the insulating element about the entire circumferential extent ofthe ring and being arranged for confinement between the body members when the parts are drawn together to effect a seal therebetween While maintaining said sealing engagement with the insulating element, a contact terminal and insulating means supporting the contact terminal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves 8 through the opening in the insulating element for engagement with the spring inside the latter.

11. In combination-in an electrical connector structure, a pair of separable parts each of which comprises a hollow body member having an opening, the parts being adapted to be placed together with the opening in one member positioned in registry with the opening in the other member, a hollow insulating element disposed within one of the body members, a coil spring disposed within the insulating element, said insulating element having an opening continuous with the opening in the one body member, the element substantially surrounding the spring to insulate the later from the one body member, means for drawing the parts together and holding the body members with their openings in registry, a resilient deformable sealing ring disposed about the opening in said one body member, said ring being in sealing engagement with the insulating element about the entire circumferential extent of the ring and being arranged for confinement between the body members when the parts are drawn together to effect a seal therebetween while maintaining said sealing engagement with the insulating element, a contact terminal and insulating means supporting the contact terminal in the other body member, the contact terminal projecting through the opening in said other body member whereby upon placing the parts together the contact terminal moves through the opening in the insulating element for engagement with the spring inside the latter, the contact terminal having a substantially uniform cross sectional shape along its length, said cross sectional shape being complemental to the shape of the opening in the insulating element to eifect a seal therewith.

12. A structure for detachably connecting a flexible conductor cable to a high frequency electrical device, said structure comprising one body adapted to be fixed to an electrical device over an opening in the latter, the body having a through passage of circular section for communicating with the interior of the device, a contact terminal extending axially through the passage, an insulating annulus embracing the terminal and closely fitted in the passage to locate and support the terminal, a button capacitor disposed across the passage and having an outer ring engaged circumferentially by the body, the terminal being axially located and abutted against the capacitor and adapted to receive axially a Wire projected through the center of the capacitor, another body having an opening registering with the through passage in the one body and a chamber continuous with such opening, an insulator recessed in the chamber of the other body, a contact spring within the insulator and electrically insulated by the later from the said other body, a passage in the said other body for receiving one end of a flexible conductor cable, the passage intersecting the chamber for projection of a wire conductor from a received cable into the body chamber for electrical connection to the contact spring, and means coupling the bodies together for facile separation and recoupling, the contact terminal being receivable within the chamber of thesaid other body upon such coupling to engage and compress the spring in effecting electrical connection therebetween, the compression of the spring maintaining yielding contact pressure against the contact terminal along an axis substantially normal to the plane the of button capacitor.

References Cited in the file of this patent UNITED STATES PATENTS 1,776,859 Johnston Sept. 30, 1930 1,959,442 Paulson May 22, 1934 2,067,614 Mascuch Jan. 12, 1937 2,113,735 Mascuch Apr. 12, 1938 2,173,643 Moser Sept. 19, 1939 2,355,116 Shumaker Aug. 8, 1944 2,397,735 Grieb u Apr. 2, 1946 2,482,763 Grimsley Sept. 27, 1949 2,540,012 Salati Ian. 30, 1951 "paw ens-a on 

